SensorInputMapperTest: migrate to InputMapperUnitTest

And make a few other small refactors while I'm at it:

* Use the actual axis constants for setting sensor types and indexes
* Inline methods that are only called once, to keep test context in one
  place
* Move test constants to the anonymous namespace rather than declaring
  and initializing them separately

Test: TEST=inputflinger_tests; m $TEST && \
      $ANDROID_HOST_OUT/nativetest64/$TEST/$TEST \
              --gtest_filter='*SensorInputMapperTest*'
Bug: 283812079
Flag: TEST_ONLY
Change-Id: I4e909c1f4e82e6a83b8c96a1fadeff56f9055861
diff --git a/services/inputflinger/tests/InputMapperTest.h b/services/inputflinger/tests/InputMapperTest.h
index fc27e4f..b6c5812 100644
--- a/services/inputflinger/tests/InputMapperTest.h
+++ b/services/inputflinger/tests/InputMapperTest.h
@@ -43,7 +43,8 @@
     virtual void SetUp() override { SetUpWithBus(0); }
     virtual void SetUpWithBus(int bus);
 
-    void setupAxis(int axis, bool valid, int32_t min, int32_t max, int32_t resolution);
+    void setupAxis(int axis, bool valid, int32_t min, int32_t max, int32_t resolution,
+                   int32_t flat = 0, int32_t fuzz = 0);
 
     void expectScanCodes(bool present, std::set<int> scanCodes);